口是心非叫逞强不叫坚强
[kŏu shì xīn fēi jiào chĕng qiáng bù jiào jiān qiáng]
This phrase reflects on the complexity of human emotions where words (speech) often do not match true feelings. It differentiates between pretending to be strong when one is actually vulnerable ('逞强', showing off being strong), and genuinely enduring difficulties with resilience and inner strength ('坚强', being truly strong).